Microwave Modified For Disinfecting

We’re all hopefully a little more concerned about health these days, but with that concern comes a growing demand for products like hand sanitizer, disinfectant, and masks. Some masks are supposed to be single-use only, but with the shortage [Bob] thought it would be good if there were a way to sanitize things like masks without ruining them. He was able to modify a microwave oven to do just that.

His microwave doesn’t have a magnetron anymore, which is the part that actually produces the microwaves for cooking. In its place is an ultraviolet light which has been shown to be effective at neutralizing viruses. The mask is simply placed in the microwave and sterilized with the light. He did have to make some other modifications as well since the magnetron isn’t always powered up when cooking, so instead he wired the light into the circuit for the turntable so that it’s always powered on.

Since UV can be harmful, placing it in the microwave’s enclosure like this certainly limits risks. However, we’d like to point out that the mesh on the microwave door is specifically designed to block microwaves rather than light of any kind, and that you probably shouldn’t put your face up to the door while this thing is operating. Some other similar builds have addressed this issue. Still, it’s a great way to get some extra use out of your PPE.

A Properly Engineered UV Chamber For PPE Sanitization

Designed to be used once and then disposed of, personal protective equipment (PPE) such as N95 face masks proved to be in such short supply during the early days of the COVID-19 pandemic that getting a few extra uses out of them by sanitizing them after a shift seemed smart. And so we saw a bunch of designs for sanitizing chambers, mostly based on UV-C light and mostly, sad to say, somewhat dodgy looking. This UV-C disinfection chamber, though, looks like a much better bet.

The link above is to the final installment of a nine-part series by [Jim] from Grass Roots Engineering. The final article has links to all the earlier posts, which go back [Jim]’s early research on UV-C sanitization methods back in March. This led him to settle on an aquarium sanitizer as his UV-C source. A second-hand ultraviolet meter allowed him to quantify the lamp’s output and plan how best to use it, which he did using virtual models of various styles of masks.  Knowing that getting light on every surface of the mask is important, he designed a mechanism to move the mask around inside a reflective chamber. The finished chamber, which can be seen in the video below, is 3D-printed and looks like it means business, with an interlock for safety and a Trinket for control.

We love the level of detail [Jim] put into these posts and the thoughtful engineering approach he took toward this project. And we appreciate his careful testing, too — after all, it wouldn’t do to use a germicidal lamp that actually doesn’t emit UV-C.

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Hackaday Links: March 22, 2020

Within the span of just two months, our world of unimaginable plenty and ready access to goods manufactured across the globe has been transformed into one where the bare essentials of life are hard to find at any price. The people on the frontline of the battle against COVID-19 are suffering supply chain pinches too, often at great risk to their health. Lack of proper personal protective equipment (PPE), especially face masks, is an acute problem, and the shortage will only exacerbate the problem as healthcare workers go down for the count. Factories are gearing up to make more masks, but in the meantime, the maker and hacker community can pitch in. FreeSewing, an open-source repository of sewing patterns, has a pattern for a simple face mask called the Fu that can be made quickly by an experienced threadworker. Efficacy of the masks made with that pattern will vary based on the materials used, obviously; a slightly less ad hoc effort is the 100 Million Mask Challenge, where volunteers are given a pattern and enough lab-tested materials to make 100 face masks. If you know how to sew, getting involved might make a difference.

As people around the world wrap their heads around the new normal of social distancing and the loss of human contact, there’s been an understandable spike in interest in amateur radio. QRZ.com reports that the FCC has recorded an uptick in the number of amateur radio licenses issued since the COVID-19 outbreak, and license test prep site HamRadioPrep.com has been swamped by new users seeking to prepare for taking the test. As we’ve discussed, the barrier for entry to ham radio is normally very low, both in terms of getting your license and getting the minimal equipment needed to get on the air. One hurdle aspiring hams might face is the cancellation of so-called VE testing, where Volunteer Examiners administer the written tests needed for each license class. Finding a face-to-face VE testing session now might be hard, but the VEs are likely to find a way to adapt. After all, hams were social distancing before social distancing was cool.

The list of public events that have been postponed or outright canceled by this pandemic is long indeed, with pretty much everything expected to draw more than a handful of people put into limbo. The hacking world is not immune, of course, with many high-profile events scuttled. But we hackers are a resourceful bunch, and the 10th annual Open Source Hardware Summit managed to go off on schedule as a virtual meeting last week. You can watch the nearly eight-hour livestream while you’re self-isolating. We’re confident that other conferences will go virtual in the near-term too rather than cancel outright.

And finally, if you’re sick of pandemic news and just want some escapist engineering eye candy, you could do worse than checking out what it takes to make a DSLR camera waterproof. We’ve honestly always numbered cameras as among the very least waterproof devices, but it turns out that photojournalists and filmmakers are pretty rough on their gear and expect it to keep working even so. The story here focuses (sorry) on Olympus cameras and lenses, which you’ll note that Takasu-san only ever refers to as “splash-proof”, and the complex system of O-rings and seals needed to keep water away from their innards. For our money, the best part was learning that lenses that have to change their internal volume, like zoom lenses, need to be vented so that air can move in and out. The engineering needed to keep water out of a vented system like that is pretty impressive.

Windows 95 Running On An N95


We’ve had this same hack submitted by two people, pointing to two different(translated) sources(translated) today. It seems with a recent version of dos box, you can load windows 3.1 or windows 95 on N95 or N85 devices. They’re both in polish, so they may be the same people posting in different places.  If you can follow along, there seems to be sufficient information to do this yourself. We don’t know why you would want to, but you could. You can see a video of it in action after the break.

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BlackBerry Storm Click Screen Teardown


RIM has decided to venture into the touchscreen phone market with the new BlackBerry Storm. Unlike other companies’ offerings, the Storm has a touchscreen that clicks when you press it. phoneWreck disassembled the Storm to see what magic was involved in the device. There’s not much too it, it’s just a big button. pW notes that the entire phone board is very compact mostly due to RIM using Qualcomm’s latest MSM7600 chip. Items like bluetooth, GPS, and USB are all included in the processor instead of appearing on the board as discrete components.

phoneWreck recently launched and promises many future teardowns. They’ll be adding to their archive which already includes the Motorola Krave and the venerable Nokia N95. We’ll definitely be watching for their future releases.

[via Engadget]

Flickr Photo Bike

Lifehacker’s [Gina Trapani] has one of Flickr’s photo bikes and wrote up how it works. As you ride, the bike automatically takes photographs, geotags them, and uploads them to Flickr. The handlebar unit contains a Nokia N95 cellphone. The rear is a solar powered charging unit. It has a custom python script that starts the photo taking sequence when it detects the bike is in motion using the phone’s accelerometer.

Most of the engineering seems to be for usability’s sake. We’re guessing they probably wanted to disguise that they’re bolting a $600 cellphone to a bike as well. Out of the box the Nokia N95 already does almost everything required. It has a 5 megapixel camera with an interval timer that can vary from 10 seconds to 30 minutes. It supports Flickr uploading, but with software like ShoZu you can streamline the geotagging and make all uploads automatic. Just build a solid mount for your N95 and you’ve pretty much got it, and when you park your bike you can take the phone with you.

In The Lab: SIM Reader

Adafruit Industries sent us one of their SIM Reader kits a few weeks ago to test. Assembly was a breeze thanks to the through hole components and good documentation. We plugged it into our USB -> RS232 converter and tried out the provided pySimReader software. It worked fine, but our modern SIM card out of an N95 didn’t prove very interesting. It was too new to attempt cloning and being a smart phone it doesn’t rely on the SIM for storing anything unless you specifically tell it to. The story was the same for a SIM we pulled out of a Treo. We tried the device with [Dejan]’s SimScan and a copy of Woron Scan. Both worked without any issue. Conclusion: the device works great despite us lacking anything interesting to do with it.